1. Field of the Invention
This invention relates to particulate material handling and operation of belt conveyors.
2. Description of the Prior Art
During travel of a mass of dry particulate material on a rubber conveyer belt, especially belts of long length, vibrations develop because of the oscillation of the belt in the vertical direction between the idler rollers. Such oscillation provides that the finer of the particles on the belt move downward toward the belt and contact it and adhere thereto. The electrostatic effects developed by result of friction of the belt with the driving and driven pulleys and idler rollers and the high electrical resistivity of the belt develops electrostatic forces between the belt and the fine particles which provides that in the normal course of events electrical charges accumulate both on the interior surface of the belt, and by induction, on the exterior surface of the belt. This in turn interferes with and or prevents the discharge of solid fine particles from such belt surfaces when such material passes over the driving or discharge pulley of such belt to the point of intended discharge of material from such belt and so provides a build up of such solid fine particles from such belt surfaces when such material passes over the driving or discharge pulley of such belt to the point of intended discharge of material from such belt and so provides a build up of such fine particles and adherence of such fine particles to the adjacent portion of the surface of the belt. On the return path of the belt during which path of travel the belt surface facing downward is the belt surface which had theretofore been contacted by the fine particles the fine particles not dropped from the belt portion at the intended point of discharge (during the interval of time during which the belt portion carrying such particles was in the zone at which such particles might have passed to the intended discharge path) are dropped from the belt along the space below the belt between the drive pulley and the conventional driven pulleys of such belts and creates an accumulation of dust which is a hazard both to health of operators and as to fire development. By the apparatuses of this invention accumulations of such particulate material on the belt is avoided.